1. Field of the Invention
This invention relates to curable compositions suitable for use as transparent, electrically conductive coatings.
2. Description of the Prior Art
Destaticization is generally required of semiconducting wafer vessels and electronic and electrical appliances. To this end, antistatic coatings are known which contain particulate carbon or metal. Alternatively, carbon particle- or metallic fiber-filled resins have been proposed for use as integrally destaticizable materials. These prior materials are not wholly satisfactory as the resulting coats and moldings are opaquely colorable.
Japanese Patent Laid-Open Publication No. 57-85866 discloses a coating composition in which particulate tin oxide is combined as an electrically conductive componentwith a binder. This coat, though transparent and antistatic, is susceptible to abrasive wear and also to solvent attack because the binder is thermoplastic in nature.
In Japanese Patent Laid-Open Publication No. 60-99176, a certain compound is used as a coating binder, which compound is derived by combining electrically conductive tin oxide-based particles with an acryloyl or methacryloyl group-containing oligomer and a maleic anhydride-added isoprene polymer, followed by partial esterification. A further coating composition involves the use of binders made up of tin oxide comminuted and an oligomeric or monomeric material having in the molecule one or more radical-reactive unsaturated groups and one or more hydroxyl groups as taught in Japanese Patent Laid-Open Publication No. 60-219270. Such known coatings excel in ultraviolet curing, electrical conductivity, hardness and solvent resistance, but fail to give sufficient transparency and adequate abrasion resistance. Tin oxide comminuted, because of its greater specific gravity than organic binders, is difficult to homogenize, and if not impossible, is liable to precipitate.